Hey guys...I have a sohc Z6 and i never could feel or hear anything near 4800 crossover. I searched and found similar problems but nothing the same. I understand that the crossover will be pretty weak but with i/h/e (tenabe super loud as hell medallion) you'd think id be able to at least hear a little tone change. For a while i just accepted it as a weak motor w/ weak crossover (even tho theres only 75k on it and still runs strong). kinda threw me off the last couple days when in second at like 6 grand and sometimes a little higher motor starts to pull and tone is much louder. I have driven vtec b16's before and felt a real crossover and this is similar to what it feels like (of course not as strong) but 2nd at real high rpm's is the only time i feel ANYTHING AT ALL.

Could this be a defective selanoid? tps? speed sensor? Kinda puzzled by this one


[Modified by amber-bling, 8:42 PM 2/3/2003]

 

I think vtec's for sohcs are more for fuel efficiencies rather than performance such as dohc. I can never feel the vtec kick in an honda ive driven except for the dohc engines. For our cars, the only profile that changes with vtec is the intake part...which saves us gas if i understand correctly. the pull at 6000 could just be your peak power with your bolt-ons

 

ive never heard vtec on a d series motor that had a stock cam

 

yeah wasnt real sure...it starts whining at 4800....no pull or exhaust tone diff...then it just pulls alot different at that point...but sometimes its as late as like 7300 o well

 

down with the regular bolt ons...time to bolt on the FI

 

damn right. bolting on FI rules.

but you still wont hear vtec

 

SOHC VTEC-E isn't going to feel the same as DOHC VTEC..

I've heard you can make better power without vtec on SOHC vtec-e engines. You should unplug it and get an air flow controller.. I bet you could tune it to make more power without the vtec.

 

yeah but at least it'll be a lil quicker....seriously though guys - if you have any other ideas help me out...Hard to believe if they put the sohc vtec for fuel efficiency, cause then wouldnt they have doneit to the base models...i mean i have a sol, and granted its a heavy sob....the S model had non-vtec - there has to be a little change at crossover!?!
I had a heavily "bolt on" modified A6 then LS in my Rex and never noticed peak like that. every non-vtec honda motor i have driven has had a little spurt at like 4200 where i dunno...valves open or something? This motor is the same at 42, but then theres a bigger kick at pretty high rpm's -----ugh

someone's gotta know

 

I understand that it wont be the same as a b series - never questioned that - may consider unplugging it later once i know that my motor is fully functional - want to know what is causeing this delay, or this extra surge of power that truly feels like a crossover

 

It's just normal for honda SOHC engines to feel like that.. I know what you mean. On the other hand, so you know this - the valves are always opening and closing, that's what makes the engine breathe.

The base models didn't come with vtec because they were weaker engines, and they don't need vtec to have good fuel consumption. To make that extra little bit of power without a little increase in fuel consumption, they designed vtec for them (like the EX).

 

I recall faintly hearing vtec with a Short Ram intake. It's been about 4 years since I've had an sohc though

 

My motor is pretty loud with the AEM CAI and Mugen exhaust. But its non-vtec. If I want an all motor SOHC, would it be better to build up the internals of the d16y7 I have now, or do a mini-me and internals?

 

noting like a good old fashioned thread whoring...... thx guy

 

i dunno but for right now i am driving the z6 and i can hear my vtec engage and tone change... motor has 150k and still does decent except for normal z6 3rd gear downshift grind.

 

dammitall dude...you brought me right back to square one lol. if I should at least hear it - why is it inconsistent and nowhere near 4800?


a quick break for all especially everyone who's helping me

 

back up for somemore insight

 

^ for the night-time tuners

 

^ last try tonight

 

i can hear vtec in my y8 just fine. my friends can't hear it or feel it though, only when you drive it. you can feel it pull a little bit diff. and the tone of the engine gets higher(pitch). its just as loud as my friends gsr, just alot slower.

edit: btw, my vtec kicks at 5500rpm


[Modified by tominos, 11:16 PM 2/3/2003]

 

I bought my 97HX (VTEC-E) about 45 day ago (2500 miles put on car since). I know nothing... Except there's ALWAYS been a VERY significant change right @ 3K. Tone changes, and pull is dramatically increased - in comparison to <3K. From 1st flooring it, to crusing on the freeway in 5th (MOST noticeable). 3K is almost the exact point - very definable change in output.

Being required to commute 250 miles round trip, 1 to 3 times per week, I've noticed something else VERY predictable. Coming up to speed (freeway) mildly, or crusing, 5th (or 4th) is VERY sluggish regardless of throttle positon - Unless... I 'tap' the trottle, then it comes alive (in comparison).

If anyone could explain the 'whys' of what I'm experiencing I'd really appreciate it.

One other thing... This car LOVES a dump to 3rd @ 75mph

read-learn-read-learn-read-learn... such a vicious cycle.

 

same here, i have a y8 with a short ram intake, header, and muffler. my vtec is pretty loud, i can tell when the engine reaches 5500 rpm without looking at the tach because there's such a big difference in engine sound. also i can feel a weak increase in power.

 

my JDM D15B pulls really hard after 4500-4800...if im cruising in third and I find my self in that rev range the pull is just awesome for a 1.5 SOHC...remember that all that the JDM d15b is a vx block with a z6 head but a very wild cam...can i hear vtec? i can definetly tell by the increased power and extreme noisy engine that sumting's happening down there, whether its vtec or not im not sure but i would most likely say that tha's how vtec feels in SOHCs

 

all decent info and wuestions...but that doesnt help my question.......can we sto p whoring my thread and someone help me???i know something is wrong and need to know what

 

Some of you guys may think this is a little rice but it works and I know when vtec kicks in. Everyone knows that you can bareley here vtec on sohc engines, so in order to solve the problem, I made a vtec indicatoor light so I would know the exact moment when it kicked in. I got the idea from this website------>

http://jdmfan.com/technical/cosmetic/vtec_indicator/

At 5200 rpms that little red led lights up, and thats when my car starts to pull. Hope this helps.

*Oh yea, if you going to do this, I would suggest tapping into the spool valve wire istead of the ecu.*


[Modified by tommyboy, 10:30 AM 2/4/2003]

 

i would consider doing this once I know my car is working probperly - and once I find out why I get a big crossover into HP at high 6k's